MacViews: Put wm window animation calls behind an interface.

ui/views/widget/window_visibility_animation_aura.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_VIEWS_WIDGET_WINDOW_VISIBILITY_ANIMATION_AURA_H_
+#define UI_VIEWS_WIDGET_WINDOW_VISIBILITY_ANIMATION_AURA_H_
+
+#include "ui/views/widget/widget.h"
+
+namespace aura {
+class Window;
+}
+
+namespace views {
+
+class WindowVisibilityAnimationAura : public Widget::VisibilityAnimation {
+ public:
+  WindowVisibilityAnimationAura(aura::Window* window);
+  virtual ~WindowVisibilityAnimationAura();
+
+  void SetDuration(const base::TimeDelta& duration) override;
+  void SetTransition(Transition transition) override;
+
+ private:
+  aura::Window* window_;  // Weak. Owned by our owner.
+
+  DISALLOW_COPY_AND_ASSIGN(WindowVisibilityAnimationAura);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_WIDGET_WINDOW_VISIBILITY_ANIMATION_AURA_H_